1. Field of the Invention
The invention concerns a cosmetic composition in emulsion form.
2. The Related Art
Petroleum jelly, commercially available under the Vaseline.RTM. brand, has long been recognized as therapeutically effective against dry skin. A major negative limiting use of petroleum jelly is the greasiness of this material. Petroleum jelly operates as a barrier but does not penetrate into the skin. Transfer of this material onto clothing, therefore, readily occurs. By contrast, water-based formulations, although often less effective, do not transfer to clothing and exhibit better feel properties. Not surprisingly, water-based cosmetic compositions such as aqueous lotions and creams have garnered the main share of the market.
An approach to providing the benefits of petroleum jelly while neutralizing its greasy feel has been the preparation of aqueous petroleum jelly emulsions. Emulsifiers have been utilized to provide compatibility between aqueous and oil phases. Attempts at emulsification have not always been successful. Even when successful, the resultant product often times fails to exhibit the skin protective properties of petroleum jelly. New and improved emulsifying systems would be highly desirable.
Illustrative of the art is U.S. Pat. No. 4,760,096 (Sakai et al) which discloses a skin moisturizing preparation that includes a phosphatide, at least one C.sub.10 -C.sub.30 carboxylic acid sterol ester and at least one C.sub.6 -C.sub.12 alkanoic triglyceride in a dermatologically acceptable carrier. WO 90/01323 (Bernstein) describes a composition for preventing dry skin based on a lipid concentrate combining three naturally-occurring lipid groups found in the stratum corneum. These groups include fatty acids, sterols (e.g. cholesterol) and sterol esters, and phospholipids and glycolipids (e.g. lecithin and ceramides). U.S. Pat. No. 4,855,090 (Wallach) approaches the problem through the use of liposome technology. A nonaqueous lipophilic phase is combined with an aqueous phase under high shear mixing conditions to form the liposomes. Among the components included in the lipophilic phase are cholesterol and polyoxyethylene fatty ether surfactant while the aqueous phase contains phsophatides such as lecithin.
In this area of technology, further improvements are desirable with respect to skin conditioning and product stability.
Accordingly, it is an object of the present invention to provide a cosmetic composition for skin which exhibits improved moisturization and provides greater protection against dry skin condition.
It is a further object of the present invention to provide a cosmetic composition for skin which has improved storage stability.
These and other objects of the present invention will become more readily apparent from the detailed description and examples which follow.